1,720,982 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
RBP1 bioactive glass-ceramic films obtained by Pulsed Laser Deposition
No full textThe deposition of thin films of bioactive materials is an issue of scientific and technological interest due to the possibility to combine mechanical strength of the implants and the bioactive properties of their surface. In this contest, we have deposited thin films of a bioactive glass-ceramics target of innovative composition by using the Pulsed Laser Deposition (PLD) technique. The deposition mechanism and the obtained films have been fully characterized by microscopic and spectroscopic techniques. It has been showed that films produced by nanosecond PLD are formed by the coalescence of nanometric droplets and films surface roughness can be suitable for the cell adhesion
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Pulsed laser-deposited composite carbon–glass–ceramic films with improved hardness
No full textA composite material obtained by mixing a glass–ceramic powder and C60 has been used to obtain thin films by nanosecond pulsed laser deposition technique, with the aim to improve the mechanical properties of the potentially bioactive coatings. Films have been deposited by using a Nd:YAG laser source (λ = 532, τ = 7 ns, 10 Hz) on titanium substrates heated at different temperatures. The deposited coatings present a sub-micron homogeneous texture completely covering the substrate with micrometric inclusions distributed on the whole surface, as observed by AFM and SEM. IR and XRD spectra of films are characteristic of amorphous calcium silicate materials, suggesting that the carbonaceous component inhibits the glass matrix crystallization, also at high deposition temperatures. Micro-Raman measurements evidence that fullerene transforms into amorphous carbon and reduced graphene oxide (RGO)-like domains in films deposited at room temperature and 500 °C, respectively. The presence of the RGO-like domains embedded in the amorphous glassy matrix has been related to the observed improved Vickers microhardness
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Raman spectroscopy discriminates malignant follicular lymphoma from benign follicular hyperplasia and from tumour metastasis
No full textRaman spectroscopy is a non-destructive label-free technique providing biochemical tissue fingerprint. The objective of the present work was to test if Raman spectroscopy is a suitable tool to differentiate lymph nodes affected by different conditions, such as reactive follicular hyperplasia (benign), follicular lymphoma (low grade primary tumour), diffuse large B cell lymphoma (high grade primary tumour) and tumour metastasis (secondary tumours). Moreover, we tested its ability to discriminate follicular lymphomas by the tumour grade and the BCL2 protein expression. Lymph nodes collected from 20 patients, who underwent surgery for suspected malignancy, were investigated. Imaging of tissue areas from about 400 μm2 up to 2 mm2 was performed collecting Raman maps containing thousands of spectra. Partial least squares discriminant analysis (PLS-DA) - a bilinear classification method - was used to calculate lymph node classification models, in order to discriminate at first between benign and malignant tissues and successively among cancer types, grades and the BCL2 protein expression. This proof-of-concept study paves the way for the development of clinical optical biopsy tools for lymph node cancer diagnosis, complementary to histopathological assessment
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
